Sealing members have been used to isolate and protect areas, substrates, and enclosures from environmental effects or other external influences. Such sealing members have been used in various applications, including the sealing of wires or contact pins or other components entering a connector for electronic devices to prevent contamination and damage to the electronics or other sensitive components.
Known methods of sealing wires or contact pins include the use of grommets or similar compression seals, heat shrinkable sealing sleeves, and articles containing greases. The use of greases presents difficulties because greases lack any type of three-dimensional structural network. Instead, greases are viscous and flow when subjected to temperature and humidity cycling, making articles of greases relatively unstable for sealing the wires or contact pins. The use of greases also renders inspection or repair difficult since greases, once applied, are difficult to remove. Other methods of sealing employ epoxies and other adhesives, but they are disadvantageous in that reentry of the wires or contact pins is difficult.
U.S. Pat. No. 4,662,692 to Uken et al. describes a method of using a layer of gel to seal contact pins. The gel is surrounded on its sides, but not on either face, by a container for ease of handling. Subsequent to being cured, the gel is disposed adjacent a terminal block usable for connecting the electrical contact pins with the block, and such that an opposite exposed face of the gel is not covered by the container which allows the electrical contact pins to be inserted there through so as to pierce through the gel and therefore be capable of making contact on the block side of the gel.
U.S. Pat. No. 4,875,870 to Hardy et al. provides an improved article of the type disclosed by Uken et al. for sealing a multiconductor connector in which the gel container is provided with special securement means to improve the compression on the gel and hence improve the performance of the seal. It also discloses articles suitable for sealing to contact wires and/or pins entering a connector. One such article uses a layer of gel supported in a container along its edges and by a base on its back surface. The front surface of the layer of gel faces the connector, and the container can be moved relative to the connector to compress the gel between its front surface and back surface to seal the connector. In another embodiment, holes for the pins and/or wires are preformed in the layer of gel so that the gel is not deleteriously damaged during insertion of the pins and/or wires. When the gel is subjected to compression, the preformed holes in the layer of gel seal up against the wires trailing from the contact pins.
It has now been discovered that a more robust method of applying and compressing the gel without the use of the container may be advantageously adapted to a wider range of applications.